Process for the manufacture of furfuryl alcohol and methylfurane



Dec. 17, 1929. ERICARD ET AL 1,739,919

PROCESS FOR THE MANUFACTURE OF FURFURYL ALCOHOL AND METHYLFURANE Filed Dec. 29. 1927 v Patented Dec. 17, 1929 UNITED STATES PATENT ori-rcs ELOI RICARD AND HENRI MARTIN GINOT, OF MELLE, FRANCE, ASSIGNORS TO SOCIETE ANONYME DES DISTILLERIES DES DEUX-SEVRES, OE NELLE (DEUX:

SEVRES), FRANCE PROCESS FOR THE -MANUFACTURE OF- FURFURYL ALCOHOL ANI) METHYLFURANE Application filed December 29, 1927, Serial No. 243,376, and in France January 31, 1927.

Various researches have been made inorder to obtain the catalytic hydrogenation of furfurol and to recognize the products of the reaction. Nickel, platinum, palladium and the oxides of platinum have been proposedas catalysts. Nickel in particular hasbeen employed by-Padoa and Ponti, who caused'it to act at 190-200 degrees C. upon hydrogen and the vapor of furfurol. The other catalysts have been employed in Wet processes. In all cases, the product of the hydrogenation is a complex mixture. In fact, the action of the hydrogen commences by the conversion of the furfurol into furfuryl alcohol, but it does not stop at this point, and it even proceeds as far as the formation of normal amyl alcohol. Various papers on this subject refer to the formation of the following products/: furfuryl alcohol, a methylfurfurane, tetrahydrofurfurylio alcohol, normal amyl alcohol, secondary amyl alcohol, methyl-propyl-ketone,

' 4pentanediol-1-2, pentanediol-1-5, tetra-hy- Y and secondary pentanol-2.

dromethylfurane. n

On the other hand, certain authors state that the hydrogenation of furfurol vcauses a rapid diminution inthe activity of the catalysts; for instance Kaufmann and Roger Adams show the necessity of renewing the activity of the platinum oxide during the hydrogenation of a given amount of furfurol in .order to complete the reaction.

The nickel used by Padoa and Ponti for the hydrogenation of furfurol vapor also loses its activity rapidly, and this Will no doubt explain the smallvamount of the hy,- drogenated product ,(30 c. c.) obtained by the authors for determining the nature of the resulting substances which consisted of furfuryl alcohol, methylfurane or sylvane, tetrahydro-a-methylfurane, propylmethylacetone,

`We have found that the hydrogenation of furfurol may be eected in an approved manner in the presence of copper as a catalyst, and the reaction hardly produces any other bodies than furfuryl alcohol and methylfurane or sylvane, which can be readily separated from one another. Also, the catalyst Will preserve its activity for a long time, and' this is a mostl important feature. f

This process for the manufacture of furfuryl alcohol and methylfurane is the object of the present invention. In this process We preferably operate in the presence of an eX- cess of hydrogen which is constantly returned to the catalyst. This latter is obtained by the reduction of copper oxide. prepared by the usual methods of precipitation and calcination. It is advantageous to employ backing substances such as asbestos, pumice stone,

'kieselguhn silica, kaolin or the like, and to give the catalyst a suitable form enabling a ready circulation of the gas.

.In the drawing We have illustrated diagrai'nmatically one embodiment of the apparatus in which the process herein described may be carried out.

The copper oxide is preferably reduced at a. low temperature, for instance 14C-200 degrees C. The furfurol is vaporized in a ourrent of hot hydrogen and is circulated upon the catalyst which is brought to the proper temperature by suitable heating means. The

reaction commences at degrees C., and at degrees C. it is already very active, Whereas Padoa and Ponti state that with nickel they use a temperature of 190-200 degrees C., which is much above the boiling point of furfurol (162 degrees 0.). The reaction continues Without complication above 220 .degrees C. It is of an exothermicnature. The proportion of methylfurane Iproduced will increase With the temperature of thefreaction.

. speed of the reaction constant, The proportion of the methylfurane, which varies Wit? the rate of supply, is about 10 to 20 per ce t of the-furfuryl alcohol formed whenopef'- ating with a fresh catalyst at'140 degrees C.

When the catalyst has become 1nactive,itv dustrial standpoint, have hitherto been preis again made active 'by very gradually passpared only in the laboratory and in very ing a current' of hot air ,through it; the tar small uantities. The resent invention, by substances deposited on the catalyst or on the which t ey can now be o tained in large quantube itself are burned out, and the copper is tities, also covers these substances considered converted into oxide. It can be reduced in as f new vmanufactured products. Finally, the tube itself, and the catalystis thenf ready the methylfurane will form an excellent liqfor use.

During the hydrogenation of the furfurol, the vapor discharged from the apparatus is condensed by cooling and the excess of hydrogen is returnedto the circulation. The conuid fuel for use. in internal combustion engines.

f EmampZe.- Let it pe supposed that the furfurol is to be converted into methylfurane. In the catalyzinggi-furnace 1, heated to l140 densed liquid contains furfurol, furfuryl aldegrees C. by suitable means such as steam, cohol, methylfur'ane and water.

.The methylfurane Which'boilsv at 65 deper catlyst which has been disposed in such grees is readily removedy by ordinary disform that it will oiferbut little resistanceto tillation. 'On the contrary the furfurol whose the gas current. I boiling point is 162 degrees and the furfuryl The current of hydrogen suppliedY by a alcohol, whose boilingpoint is 171 degrees, vblower' 17 will proceed through the externally cannot be readily separated by the usual disheated vaporizer 3 and will vaporize the furtillation, since their boiling points 'are near furol which is supplied by the pipe 4. A together. We have observed that they may float-feed tank 5 is used to obtain the regular be' separated with facility by taking advanfeed. tage of the following actions.

Furfurol forms with water a mixture havif hydrogen enters the catalyzing furnace; it ing a minimum boiling point, which contains passes in vthe first place through the annular 35 per cent of furfurol, and whose boiling space 2 and then upon the catalyst disposed point is 97 de ees. After condensation,this at 6. A reaction will take place, with, dismixture can e decanted; the furfurol thus engagement of heat, but this ofersno prejuseparates out, and it can be again used in the dice to the operation in virtue of the arrangecirculati'on for the hydrogen process. In this ment we adopt for counter-How circulation, manner, to separate all the fu-r'furol, it need whereby all excess of temperature is obviated. only be distilled in the presence of water. The vapor issuing from the catalyzing fur- On the contrary, the furfurylic alcohol will nace ,passes through a water condenser 7 and not form, with water, any such mixture hav then into a brine condenser 8, so that the consmall amount of furfuryl alcohol will be disarated.

tilled over with the water, but this amount is a Since hydrogen is consumed in the re very small b reason of the greatL-diiference action, a suction or vacuum will be produced between the boiling points of these two subat the f' point 11'12 of the apparatus, thus stances. Toremove this small quantity of drawing in fresh hydrogen from the gas furfurvl alcohol from the water with. whichA tank 9through the pipe 10. The-gas which it has been brought over, 'it is simply neceshas not reacted, and also the fresh hydrogen, sary to proceed with the usual rectification are taken up by the blowei' `17 and areagain of the vapors, sov that the water will come over circulated upon the catalyst.

electric current or the like, weplace the cop-- The mixture of the furfurol vapor and in the irst place and the furfuryl alcohol will remain in the pure state 'at the end of the distillation.

These operations take place at atmospheric pressure,.or preferably in vacuo,

We have also observed that furfuryl alcohol when used alone or mixed'with furfurol,

will be hydrogenated in the same conditions as furfurol alone, and it thus produces mcthylfurane, so that if only the methylfurane is removed from the products of the hydrogenation, and if the mixture of furfurol and furfuryl alcohol is pashed through the catalyst tube, all of the original furfurol small amount of can be converted into methylfurane. owever, there will bev produced in all cases a h (l tetrahydrofurfurylic alco- The furfuryl alcohol and the inethylfurane, which posses valuable properties from an in of furfurol,f urfuryl alcohol and a small proportion of water, which is allowed to settlein ing a minimumeboiling point. However, a densed liquids can be automatically 'septhe decanting 'vessel 15 and is then sent into the feeding. tankA b the elevating pump 16, for asubsequent ydrogenat-ion. In this manner the furfurol will be almost entirely converted intomethylfurane at the end of the process. e

What we claim is 1. Process for the manufacture of products ef the hydrogenationof furfurol, which conslsts in mixing thevapor offurfurol with a great excess of hydrogen, vand in circulating thecmixture upon copper acting as a catal st. v

2. rocess for the manufacture of furfurol f alcohol and methylfurane,

l methylf-urane and water,

Aproducts upon copper .hailing remove alcohol and methylfurane by the hydrogenation offurfurol which consists in mixing the vapor of furfurpl with a great excess of hydrogen, and in circulating the mixture upon copper acting as la catalyst.

` 3. Process for the manufacture of products Y, of the hydrogenatlon of furfurol; which consists in mixing the vaporfurfurol with a great excess of hydrogen, and in circulating the mixture upon copper acting as a catalyst, the excess of .hydrogen being again mixed with furfurol vapor for a further circulation -upon the catalyst.

4. Process for the manufacture of products of the hydrogenation of furfurol, whichconsists in mixing the vapor of furfurol -with a great excess of hydrogen /and incirculating themixture upon copper acting as a catalyst,

saidV catalyst being heated grecs l 5. Process'for the manufacture of furfuryl alcohol and Amethylfurane which consists 1n vaporizing the furfurol in a current of hot hydrogen in excess; and in circulating the heated to at least 80 to at least 80 dedegrees C.

' 6. Process for the manufacture of furfuryl alcohol and methylfurane which consists 1n vaporizing the furfurol in a current` of hot hydrogen in excess, and in circulating thel products upon copper heated to at least 80 degrees C., said copper being obtained by the 'reduction of ,copper 'oxide' and being placed upon a catalyst carrier so disposed as to facilitate the gas circulation. t

7. Process for the manufacture offurfu l alcohol and methylfurane, which consists 1n vaporizing tl1e-furfurol in a current of hot hydrogen in excess, in circulating the. mixturelu on copper heated to at least 80 degrecs in condensing the vapor discharged from the ap aratus, the condensed li uid containing. rfurol, furfurylic alco ol, methylfurane and water.

8. Process for the manufacture of furfuryl vaporizing the furfurohin a current of hot hydrogen in excess, in circulating the mixture u on copperA heated to at least 80 derees in condensing thevapor discharged om the apparatus, the condensing li uid containing 1 furfurol, fur-furylic alco ol, in distilling the condensedliquid in such manner as tol remove the methylfurane which is distilled oif in the rst place, Whereas the fufurol and the water form a mixture having a minimum point, in decantingthis mixture to the furfurol, in placin this removed furfurol again in the circ ation, 'and in treating the' remaining mixture of the distillation to remove the furfuryl alcohol.

9. In a process for the manufacture of hydrogenated,products of furfurol, the use of aA catalyst consisting of copper obtained,

by the reduction of copperA Aoxide at 140 to 200 degrees C., said copper .being placed upon the'. catalyst carriers'which afe 1n common use for catalysts. v

10. Process for the manufacture of methlfurane which consists in vaporizing furfurol in a current of hot hydrogen in-excess, in circulating the mixture upon copper heated to at least'80 degrees C., and in condensing the vapor discharged from the apparatus, the condensed .liquid containing furfurol, furfuryl alcohol, methylfurane and water, in distilling the condensed `li uid in such manner as to remove the methyl urane, in decanting the liquid resulting from the distillation, and in again causing the furfurol and the .furfuryl i enter the operating circulation.

In testimony whereof we have signed this specification. 'v

ELOI RICARD.'

HENRI MARTIN GUINoT. I

which consists 1n alcohol thus removed to 

